Abstract
Article described capitalist social life of modern Japanese that was having individualistic characteristic. This high individualistic life affected the availability of disconnected family life called muenshakai. This phenomenon caused social and economic shifts in the Japanese family. This research used qualitative approach elaborated in descriptive analysis. The object of research or data corpus was the problem of a decline in Japan population in terms of the breakdown of the family. The research results indicated that muenshakai phenomenon has emerged in Japan caused by some sequential events, those are: the 2nd World War "legacy', the availability of baby boom, the abolition of shuushinkoyou, the decreasing of marital rate, the increasing of divorce rate, the decreasing of birth rate, and the lost of family relationship. It can be concluded that the urban individualistic life style is able to change the traditional thinking pattern into opportunistic one that becomes one of the causal factors of muenshakai phenomenon.
